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From:   Valentin Schneider <valentin.schneider@arm.com>
To:     linux-kernel@vger.kernel.org
Cc:     mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org,
        dietmar.eggemann@arm.com, morten.rasmussen@arm.com
Subject: [PATCH v3 3/7] sched/topology: Verify SD_* flags setup when sched_debug is on
Date:   Wed,  1 Jul 2020 20:06:51 +0100
Message-Id: <20200701190656.10126-4-valentin.schneider@arm.com>
In-Reply-To: <20200701190656.10126-1-valentin.schneider@arm.com>
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Now that we have some description of what we expect the flags layout to
be, we can use that to assert at runtime that the actual layout is sane.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
---
 kernel/sched/topology.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 9079d865a935..b3f891db16a7 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -29,6 +29,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
 				  struct cpumask *groupmask)
 {
 	struct sched_group *group = sd->groups;
+	int flags = sd->flags;
 
 	cpumask_clear(groupmask);
 
@@ -43,6 +44,22 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
 		printk(KERN_ERR "ERROR: domain->groups does not contain CPU%d\n", cpu);
 	}
 
+	for (; flags; flags &= flags - 1) {
+		unsigned int idx = __ffs(flags);
+		unsigned int flag = BIT(idx);
+		unsigned int meta_flags = sd_flag_debug[idx].meta_flags;
+
+		if ((meta_flags & SDF_SHARED_CHILD) && sd->child &&
+		    !(sd->child->flags & flag))
+			printk(KERN_ERR "ERROR: flag %s set here but not in child\n",
+			       sd_flag_debug[idx].name);
+
+		if ((meta_flags & SDF_SHARED_PARENT) && sd->parent &&
+		    !(sd->parent->flags & flag))
+			printk(KERN_ERR "ERROR: flag %s set here but not in parent\n",
+			       sd_flag_debug[idx].name);
+	}
+
 	printk(KERN_DEBUG "%*s groups:", level + 1, "");
 	do {
 		if (!group) {
-- 
2.27.0